Characteristics of bypass-current MIG-TIG double-sided welding of stainless steel

By using 6mm thick 304 stainless steel plate as base metal,the bypass-current double-sided arc welding experiments were carried out.The results showed the technology can obtain the stable process and good weld appearance.The other remarkable advantages such as increasing joint penetration,deceasing welding defects,enhancing production efficiency,reducing welding cost were also achieved.The reliable joining of 6mm thick 304 stainless steel was realized at welding current of 110 A.Furthermore,the melting efficiency of bypass-current doublesided arc welding can reach 60.2%,more than 17.6% of TIG welding and 43.2% of bypass-current MIG welding.The tensile results showed the strength of the joints can reach 776.5MPa,about 95% of that of base metal.The fracture occurs at the heateffect zone,and the angle between fracture line and stress direction is 45°.The fracture appearance is gray,which shows the characteristics of ductile fracture.